The amino acid, L-arogenate, is widely utilized by both microorganisms and higher plants as a precursor of L-phenylalanine and L-tyrosine. It is of increasing importance in both basic university-sponsored research and in applied research within industry to have access to L-arogenate as a substrate for a number of newly described enzymes, for use in various nutritionally and physiological experiments, for use as authentic standards, and for use as starting material in the making of derivative compounds. Because of the placement of the compound within diverse patterns of aromatic-amino-acid pathway construction and regulation, derivatives of L-arogenate have potential for design of antimicrobial and herbicidal compounds. L-Arogenate is currently produced at great expense (> $10 per mg) as a minor accumulation entity in Neurospora crassa, in an initial preparation heavily contaminated with other cyclohexadienyl compounds produced from prephenate. A strategy is proposed for construction of a multiple mutant of Brevibacterium flavum that is expected to increase the yield of L-arogenate by a factor of 10-to-100 or more, with little or no side-production of interfering cyclohexadienyl compounds.